If you really want a detailed simulation of an A-10 try Lock-On: Modern Air Combat
. Really good in depth simulation that was just released recently. Other flyable planes are the F-15C, Su-27, Su-33, Su-25, and the MiG-29. Graphics and flight dynamics are top notch, and so is the included mission generator.
Made by the same guys who did Su-27 Flanker and Su-27 Flanker 2.0/2.5.
Community support and forums are top notch and there is quite a big following. Definitely worth checking out for you simulation junkies.
[Edited 2004-07-26 05:53:16]